The cable TV and satellite TV industries have long needed an online program guide. An online program guide would be broadcast over a satellite or cable system, and the received program information would be stored in a satellite receiver, cable TV decoder or other unit. An online system would eliminate paper TV guides, which are difficult to distribute and often inaccurate because of last minute changes in TV programming. Moreover, with the availability hundreds or thousands of TV reception channels for satellite TV, paper guides have become bulky and difficult to use.
An online TV program information system would allow storage of up-to-date information for many services, and may provide searching capabilities for the stored TV schedule information, so that only desired channels, services or types of programming are selected. The TV program information may be displayed on the TV to allow searching and viewing. See for example U.S. Pat. No. 4,751,578 to Reiter et al. entitled System For Electronically Controllably Viewing On A Television Updatable Television Programming Information, in which TV programming information is stored, under microcomputer control, and a remote control system permits the viewer to direct the microcontroller to perform searches on stored information to provide subsets of information desired by the viewer.
Another known advantage of an online TV schedule system is the ability of the selected TV program information to control a video cassette recorder (VCR) or satellite reception antenna. For example, one week of programs may be selected for future viewing. At the selected times the TV may be turned on and tuned to the proper channel, a VCR may be activated for recording or a satellite dish may be aimed and tuned for proper reception. See for example U.S. Pat. No. 4,706,121 to Young entitled TV Schedule System and Process, in which a system controls a TV to allow user selection of broadcast programs from schedule information which is received from an FM receiver under system control. User inputs are supplied and a data processor selects programs from the schedule information based on the user inputs. A programmable VCR may be controlled by the data processor based on the user inputs.
Notwithstanding the above described advantages and long felt need, a large scale online TV program system has not heretofore been commercialized, primarily because of economic considerations. The unit for receiving and storing online TV schedule information (whether freestanding or included in other devices) must be inexpensive to produce and sell. However, in order for such a unit to be useful, at least a few days and preferably at least a week or more of schedule information must be stored therein. For a satellite TV system, one week of information may consist of 10,000 distinct events (i.e. a unique show at a unique time) including 2,000 different shows. An inordinate amount of memory is required to store this much information, including necessary descriptions of the shows. Moreover, in order to efficiently process this much information, for example for program searching, high speed processors are required.
The combination of high performance processors and large memory requirements have made the devices prohibitively expensive. A system which included sufficient processing power and memory to store a critical amount of TV schedule information was too expensive to gain widespread acceptance, while an affordable system could not store enough schedule information to be useful. This situation has not improved as the cost of processors and memory have decreased, because the ever increasing number of available TV services has required ever increasing amounts of memory and higher processor speeds for the TV program information.